This invention relates to chop saws and particularly to a combination chop and table saw, otherwise known as a flip-over saw. In particular, the invention relates to such a saw which is capable of making bevel cuts in both its table saw mode and mitre saw mode. Such a saw is described in U.S. Pat. No. 4,531,441.
Combination chop and table saws commonly consist of a table, to which is affixed a pivot block, and a pivot support pivotable relative to the pivot block about a horizontal axis. This horizontal axis is the bevel axis of the saw. The pivot support carries the saw assembly including the mechanical saw blade. It is commonplace for there to be some kind of latch arrangement between the pivot block and the pivot support, such that the two will latch together at a number of commonly used angular positions, for example with the saw blade at 15 degrees, 22.5 degrees, 30 degrees or 45 degrees from the vertical. Such latch arrangement is normally provided with a scale which is visible from the front of the saw, even though it is at the back of the saw from a user""s perspective.
However, with a saw capable of being used in a table mode as well as a chop mode, it is difficult to ascertain the bevel angle in the table mode, since the pivot block and pivot support are then located underneath the table when the table is inverted. Although the scale is now at the front of the saw, it faces away from the user.
It is an object of the present invention to provide a saw in which it is relatively easy to identify the angle which the saw blade makes to the vertical. Accordingly, the invention provides a saw comprising a workpiece support having a first substantially planar surface, a pivot support pivotally mounted with respect to the workpiece support about a first axis, a mechanical saw blade pivotally mounted with respect to the pivot support about a second axis, the first axis being substantially parallel to the surface of the workpiece support and substantially coincident with the plane of the saw blade, the second axis being substantially perpendicular to the first axis and the plane of the saw blade, and a gearing mechanism coupling the workpiece support and the pivot support to a dial such that the dial indicates the angle between the surface of the workpiece support and the plane of the saw blade. The bevel angle of the saw can easily be identified by inspection of the dial.
For ease of construction, it is preferred that the gearing mechanism comprise a rack and pinion. The rack may be carried by a pivot block fixed to the workpiece support and the pinion may be carried by a spindle rotatably journalled in the pivot support. Since, as the bevel angle of the saw is adjusted, the pivot support moves relative to the workpiece support and therefore to the pivot block, such adjustment will cause the pinion to advance along the rack and therefore will cause the spindle to rotate relative to both the pivot block and the pivot support.
Preferably, the dial comprises a pointer and a scale, one of which is attached to the pivot support, the other to one end of the spindle.
So as to make inspection of the dial easy when the saw is being used in its table mode, it is preferred that the dial faces the position where the operator would be standing. Thus, as the workpiece support will normally include a slot to receive the saw blade, it is preferred that the dial be positioned with respect to the pivot support so as to face away from the slot. The invention also provides a saw comprising a frame, a table mounted in the frame and adapted to pivot between two positions of the table in the frame, a pivot block on one side of the table, a pivot support pivotally mounted with respect to the table about a first axis coincident with the plane of the table, a saw assembly mounted on the pivot support and comprising a motor driven saw blade lying in a plane coincident with said first axis, a slot in the table to one side of said pivot block and pivot support, the saw assembly being adapted to move said blade in its plane through said slot, and a gearing mechanism between said pivot block and pivot support coupled with a dial on said other side of said pivot block and pivot support whereby the rotational position of said pivot block to said pivot support about said first axis is indicated.
The gearing mechanism may comprise an arcuate rack and a pinion, the dial being operatively connected to said pinion. Moreover the pivot block is preferably between the slot and pivot support, in which event, the rack is disposed on said pivot block and said pinion is journalled in said pivot support.
Clamp means may clamp said pivot support and pivot block together, and may comprise a releasable bolt received in said pivot support and passing through an arcuate slot in said pivot block, which slot is centred on said first axis, said pinion being journalled on said bolt.
The saw assembly is preferably pivoted on said pivot support about a second axis substantially perpendicular to said plane and first axis.